This invention concerns an on-demand packing mechanism for flexible pouches generally used as packaging for smaller, discrete items.
Flexible pouches, formed by crimping and sealing the ends of a tubular section of cellophane, plastic wrap, or foil, are used to prepare such items as nuts, candies, other snack foods and a variety of other discrete items for sale to the individual consumer. These pouches offer a number of significant advantages over other possible containers. These advantages include lighter weight, lower cost, and ease of filling.
Case packing these flexible, irregularly-shaped pouches for shipment so as to make efficient use of space, however, has proven to be difficult. The undefined shape of the bag makes pushing, pulling, or grabbing it problematical. Conveyors have generally proven useful in transporting the bags but not for packing them in boxes. Some prior art machines have used suction cups to grip the bags. The relatively powerful vacuum required, however, together with the small area over which each suction cup acts against the bag, increases the probability of bag damage. In addition, the relatively inflexible positioning of the suction cups relative to each other prevents, to some extent, adaptability of the packing machine to different sizes of pouches.
One problem prevalent with many prior art conveyors used to transport pouches is that the conveyors have stationary sidewalls. The pouches, if misaligned or placed too far from the center of the conveyor, tend to catch against these sidewalls which slow the pouches' forward movement, thereby changing the spatial relationship and time interval between the pouches.
In addition, bags may be fed at irregular intervals into a packing machine. Most prior art machines for case packing are not suitable for packing pouches. These prior art case packing machines rely on the creation of a sizable backlog of the product, and then physically pushing the product to create rows suitable for packing. These prior machines cannot provide an on-demand packing system for pouches. The flexible and fragile nature of the pouches precludes the use of a packing technique which creates a backlog or relies on pushing the package.
Finally, no prior art packing machines adjust the spacing of the pouches, such as by nestling them together, so as to pack them as efficiently as possible.